Liquid crystal display

ABSTRACT

A liquid crystal display including a first substrate; a second substrate facing the first substrate; a thin film transistor disposed on the first substrate; an organic layer disposed on the thin film transistor; a pixel electrode disposed on the organic layer; a lower alignment layer disposed on the pixel electrode; a common electrode disposed on the second substrate; and an upper alignment layer disposed on the common electrode, wherein a first free radical included in the organic layer and a second free radical included in at least one of the lower alignment layer and the upper alignment layer are radical bonded.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to Korean Patent Application No.10-2012-0010375, filed on Feb. 1, 2012, and all the benefits accruingtherefrom under 35 U.S.C. §119, the content of which in its entirety isherein incorporated by reference.

BACKGROUND OF THE INVENTION

(a) Field of the Invention

The disclosure relates to a liquid crystal display.

(b) Description of the Related Art

A liquid crystal display is one of the most widely used flat paneldisplay device. The liquid crystal display includes two display panelseach including an electric field generating electrode, such as a pixelelectrode, and a common electrode, and a liquid crystal layer interposedbetween the two display panels.

In the liquid crystal display, a voltage is applied to the electricfield generating electrodes to generate an electric field in a liquidcrystal layer. Due to the generated electric field, liquid crystalmolecules of the liquid crystal layer are aligned and a polarization ofincident light is controlled, thereby displaying an image.

The liquid crystal display can have a greenish color. It would bedesirable to have a liquid crystal display without the greenish color.

SUMMARY

In an embodiment a liquid crystal display in which a greenish defect issubstantially or effectively reduced or prevented is provided.

A liquid crystal display according to an exemplary embodiment includes:a first substrate; a second substrate facing the first substrate; a thinfilm transistor disposed on the first substrate; an organic layerdisposed on the thin film transistor; a pixel electrode disposed on theorganic layer; a lower alignment layer disposed on the pixel electrode;a common electrode disposed on the second substrate; and an upperalignment layer disposed on the common electrode, wherein a first freeradical included in the organic layer and a second free radical includedin at least one of the lower alignment layer and the upper alignmentlayer are radical bonded.

The lower alignment layer and the upper alignment layer may each furtherinclude a functional group represented by Chemical Formula 1

wherein, m is 1-5.

The lower alignment layer and the upper alignment layer may each furtherinclude a vinyl functional group.

The lower alignment layer and the upper alignment layer may each furtherinclude a methacrylate functional group.

The organic layer may have negative photosensitivity.

The pixel electrode may include a first subpixel electrode and a secondsubpixel electrode, wherein the first subpixel electrode and the secondsubpixel electrode may each include a cross stem including a transversestem and a longitudinal stem intersecting the transverse stem and aplurality of branches extending from the cross stem.

A gate line and a reference voltage line disposed on the first substrateand a data line intersecting the gate line may be further included inthe liquid crystal display.

The thin film transistor may include a first thin film transistor and asecond thin film transistor each connected to the gate line and the dataline, and a third thin film transistor connected to the gate line, aterminal of the second thin film transistor, and the reference voltageline.

The pixel electrode may include a first subpixel electrode and a secondsubpixel electrode separated from each other, wherein the first subpixelelectrode may be electrically connected to the first thin filmtransistor, and the second subpixel electrode may be electricallyconnected to the second thin film transistor.

An assistance voltage line electrically connected to the referencevoltage line through the third thin film transistor and disposed on thedata line may be further included, and the assistance voltage line maybe disposed on a same layer as the pixel electrode.

The reference voltage line may include a protrusion overlapping oneterminal of the third thin film transistor, and the assistance voltageline may include a connecting member extending toward the protrusion ofthe reference voltage line.

An output terminal of the second thin film transistor may be connectedto the second subpixel electrode and an input terminal of the third thinfilm transistor.

Each control terminal of the first thin film transistor, the second thinfilm transistor, and the third thin film transistor may be configured tosimultaneously respond to a gate signal.

A gate line and a step-down gate line disposed on the first substrate,and a data line intersecting the gate line, may be further included inthe liquid crystal display.

The thin film transistor may include a first thin film transistor and asecond thin film transistor each connected to the gate line and the dataline, and a third thin film transistor connected to the step-down gateline.

The pixel electrode may include a first subpixel electrode and a secondsubpixel electrode separated from each other, wherein the first subpixelelectrode may be electrically connected to the first thin filmtransistor, and the second subpixel electrode may be electricallyconnected to the second thin film transistor.

A storage electrode overlapping a terminal of the third thin filmtransistor may be further included in the liquid crystal display.

Also disclosed is a method of manufacturing a liquid crystal display,the method including: disposing a first substrate, a second substratefacing the first substrate, a thin film transistor disposed on the firstsubstrate, an organic layer disposed on the thin film transistor, apixel electrode disposed on the organic layer, a lower alignment layerdisposed on the pixel electrode, a common electrode disposed on thesecond substrate, and an upper alignment layer disposed on the commonelectrode; and contacting at least one of a first free radical includedin the organic layer and a second free radical included in at least oneof the lower alignment layer and the upper alignment layer to form aproduct of the first free radical and the second free radical disposedon at least one of the lower alignment layer and the upper alignmentlayer, to manufacture the liquid crystal display.

As is further described, according to an exemplary embodiment, thesecond free radicals included in the lower and upper alignment layersmay react with the first free radical of the passivation layer of theorganic layer having negative photosensitivity such that a greenishdefect emitting light of the visible light region may be improved.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other features and advantages of this disclosure willbecome more apparent by describing in detail embodiments thereof, withreference to the accompanying drawings, in which:

FIG. 1 is a plan view of a liquid crystal display according to anexemplary embodiment;

FIG. 2 is a cross-sectional view taken along line II-II of FIG. 1;

FIG. 3 is a cross-sectional view taken along line III-III of FIG. 1;

FIG. 4 is a plan view of a liquid crystal display according to anotherexemplary embodiment; and

FIG. 5 is a cross-sectional view taken along line V-V of FIG. 4.

DETAILED DESCRIPTION

The embodiments are described more fully hereinafter, with reference tothe accompanying drawings, in which exemplary embodiments of theinvention are shown. This disclosure may, however, be embodied in manydifferent forms and should not be construed as limited to the disclosedembodiments set forth herein, but, on the contrary, is intended to covervarious modifications. Thus these embodiments are provided so that thisdisclosure will be thorough and complete, and will fully convey thescope of the disclosure to those skilled in the art. The disclosedembodiments may be modified in various different ways, all withoutdeparting from the spirit or scope of the present disclosure.

In the drawings, the thickness, size, and relative sizes of layers,films, panels, regions, etc., may be exaggerated for clarity. It will beunderstood that when an element such as a layer, film, region, orsubstrate is referred to as being “on”, “connected to”, or “coupled to”another element or layer, it can be directly on, connected to, orcoupled to the other element or intervening elements or layers may bepresent. When an element or layer is referred to as being “disposed on”or “formed on” another element or layer, the elements or layers areunderstood to be in at least partial contact with each other, unlessotherwise specified. In contrast, when an element or layer is referredto as being “directly on”, “directly connected to”, or “directly coupledto” another element or layer, the elements are in at least partialcontact with each other and there are no intervening elements or layerspresent. Like reference numerals refer to like elements throughout.

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting. As used here, thesingular forms “a,” “an,” and “the” are intended to include the pluralforms as well, unless the content clearly indicates otherwise. “Or”includes “and/or.” As used herein, the term “and/or” includes any andall combinations of one or more of the associated listed items. It willbe further understood that the terms “comprises” and/or “comprising,” or“includes” and/or “including” when used in this specification specifythe presence of stated features, regions, integers, steps, operations,elements, and/or components but do not preclude the presence or additionof one or more other features, regions, integers, steps, operations,elements, components, and/or groups thereof.

Unless otherwise defined, all terms (including technical and scientificterms) used herein have the same meaning as commonly understood by oneof ordinary skill in the art to which this invention belongs. It will befurther understood that terms, such as those defined in commonly useddictionaries, should be interpreted as having a meaning consistent withtheir meaning in the context of the relevant art, and will not beinterpreted in an idealized or overly formal sense unless expressly sodefined herein.

Embodiments are described herein with reference to cross sectionalillustrations that are schematic illustrations of idealized embodiments(and intermediate structures). As such, variations from the shapes ofthe illustrations as a result, for example, of manufacturing techniquesand/or tolerances, are to be expected. Thus, embodiments describedherein should not be construed as limited to the particular shapes ofregions as illustrated herein but are to include deviations in shapesthat result, for example, from manufacturing. For example, a regionillustrated or described as flat may, typically, have rough and/ornonlinear features. A region illustrated as a rectangle may typicallyhave rounded or curved features. Moreover, sharp angles that areillustrated may be rounded. Likewise, a buried region formed byimplantation may result in some implantation in the region between theburied region and the surface through which the implantation takesplace. Thus, the regions illustrated in the figures are schematic innature and their shapes are not intended to illustrate the precise shapeof a region and are not intended to limit the scope of the presentdisclosure.

It will be understood that, although the terms “first”, “second”,“third”, and the like do not imply any particular order, but may be usedherein to describe various elements, components, regions, layers and/orsections. These elements, components, regions, layers and/or sectionsshould not be limited by these terms. These terms are only used todistinguish one element, component, region, layer and/or section. Thus afirst element, component, region, layer and/or section discussed belowcould be termed a second element, component, region, layer and/orsection without departing from the teachings herein.

Spatially relative terms, such as “beneath”, “below”, “lower”, “above”,“upper”, and the like, may be used herein for ease of description todescribe one element or feature's relationship to another element(s) orfeature(s) as illustrated in the figures. It will be understood that thespatially relative terms are intended to encompass differentorientations of the apparatus in use or operation in addition to theorientation depicted in the figures. For example, if the apparatus inthe figures is turned over, elements described as “beneath”, “below”, or“lower” other elements or features would then be oriented “above”, or“upper” the other elements or features. Thus, the exemplary term “below”can encompass both an orientation above and below. The apparatus may beotherwise oriented (rotated 90 degrees or at other orientations) and thespatially relative descriptors used herein interpreted accordingly.

As used herein, the term “alkyl” means a straight or branched chainsaturated aliphatic hydrocarbon having the specified number of carbonatoms and having a valence of at least one, optionally substituted withone or more substituents where indicated, provided the valence of thealkyl group is not exceeded.

According to an embodiment, the liquid crystal display includes a lowerdisplay panel, e.g. first substrate and an upper display panel, e.g.second substrate facing each other. The lower display panel may includea gate line which transmits a gate signal and a data line whichtransmits a data signal, wherein the gate line and the data line mayintersect each other, a thin film transistor electrically connected tothe gate line and the data line, and a pixel electrode electricallyconnected to the thin film transistor. The upper display panel mayinclude a light blocking member, a color filter, and a common electrode.

The liquid crystal display may further include an organic layer havingnegative photosensitivity. While not wishing to be bound by theory, itis believed the organic layer facilitates high transmittance and a fastresponse speed. The liquid crystal display may further include a pixelelectrode having a slit pattern. The liquid crystal display may furtherinclude a lower alignment layer and an upper alignment layer, each ofwhich may include a reactive mesogen.

According to an embodiment, at an interface of the organic layer and atleast one of the lower alignment layer and the upper alignment layer, afirst free radical can react with a second free radical to form aproduct disposed on at least one of the lower alignment layer and theupper alignment layer. The product can include a double bond, and can behighly conjugated, thereby generating visible light, which can begreenish in color.

A liquid crystal display according to an exemplary embodiment will befurther described with reference to FIG. 1 to FIG. 3.

FIG. 1 is a plan view of a liquid crystal display according to anexemplary embodiment, FIG. 2 is a cross-sectional view taken along lineIII-III of FIG. 1, and FIG. 3 is a cross-sectional view taken along lineIII-III of FIG. 1.

Referring to FIG. 1 to FIG. 3, a liquid crystal display according to anexemplary embodiment includes a lower display panel 100 e.g., firstsubstrate and an upper display panel 200, e.g., second substrate, facingeach other, and a liquid crystal layer 3 interposed between the twodisplay panels 100 and 200.

According to an embodiment, a liquid crystal display includes a firstsubstrate; a second substrate facing the first substrate; a thin filmtransistor disposed on the first substrate; an organic layer disposed onthe thin film transistor; a pixel electrode disposed on the organiclayer; a lower alignment layer disposed on the pixel electrode; a commonelectrode disposed on the second substrate; and an upper alignment layerdisposed on the common electrode, wherein a product of a first freeradical included in the organic layer and a second free radical includedin at least one of the lower alignment layer and the upper alignmentlayer is disposed on at least one of the lower alignment layer and theupper alignment layer.

First, the lower display panel 100, e.g. first substrate, will bedescribed referring to FIG. 1 to FIG. 3.

A gate line 121 and a reference voltage line 131 are each disposed on aninsulation substrate 110, wherein the insulation substrate includes atransparent glass or a plastic.

According to an embodiment, the gate line and the reference voltage linemay be disposed on the lower display panel, e.g. first substrate, and adata line may intersect the gate line.

The gate line 121, extending in a mainly transverse direction, isconfigured to transmit a gate signal, and includes a first gateelectrode 124 a, a second gate electrode 124 b, and a third gateelectrode 124 c.

The reference voltage line 131, extending in a mainly transversedirection, is configured to transmit a predetermined voltage, such as areference voltage, and includes a first reference electrode 133 aenclosing a first pixel electrode 191 a, which will be further describedlater, and a protrusion 134 protruding in a direction of the gate line121. The reference voltage line 131, further includes a second referenceelectrode 133 b enclosing a second pixel electrode 191 b which will befurther described later. Although not shown in FIG. 1, a horizontalportion of the first reference electrode 133 a is electrically connectedto a horizontal portion of the second reference electrode 133 b of aprevious pixel by integral wiring. A gate insulating layer 140 isdisposed on the gate line 121 and the reference voltage line 131.

A plurality of semiconductor stripes 151, wherein each semiconductorstripe includes a hydrogenated amorphous silicon (a-Si), polysilicon, orthe like, are disposed on the gate insulating layer 140. Thesemiconductor stripes 151 extend in a mainly vertical direction, andeach semiconductor stripe 151 includes a first semiconductor 154 a, asecond semiconductor 154 b, and a third semiconductor 154 c.

A plurality of ohmic contact stripes 161 are disposed on thesemiconductor stripes 151. A plurality of ohmic contacts including ohmiccontacts 163 a, 165 a, and 165 c, are disposed on the firstsemiconductor 154 a, the second semiconductor 154 b, and the thirdsemiconductor 154 c, wherein ohmic contacts 163 a and 165 a are onlyshown disposed on the first semiconductor 154 a in FIG. 2, and an ohmiccontact 165 c is only shown disposed on the third semiconductor 154 c inFIG. 3 because the cutting lines of the drawing do not transverse theother portion.

Data conductors 171, 173 c, 175 a, 175 b, and 175 c, include a pluralityof data lines 171, including a first source electrode 173 a, a secondsource electrode 173 b, a first drain electrode 175 a, a second drainelectrode 175 b, a third source electrode 173 c, and a third drainelectrode 175 c. The data conductors are disposed on the ohmic contacts163 a, 165 a, and 165 c and the gate insulating layer 140. The thirddrain electrode 175 c overlaps the protrusion 134 of the referencevoltage line 131.

The first gate electrode 124 a, the first source electrode 173 a, andthe first drain electrode 175 a form a first thin film transistor Qaalong with the first semiconductor 154 a, and a channel of the thin filmtransistor is formed in the semiconductor portion 154 a between thefirst source electrode 173 a and the first drain electrode 175 a.

Similarly, the second gate electrode 124 b, the second source electrode173 b, and the second drain electrode 175 b form a second thin filmtransistor Qb along with the second semiconductor 154 b, and the channelof the thin film transistor is formed in the semiconductor portion 154 bbetween the second source electrode 173 b and the second drain electrode175 b, and the third gate electrode 124 c, the third source electrode173 c, and the third drain electrode 175 c form a third thin filmtransistor Qc along with the third semiconductor 154 c, and the channelof the thin film transistor is formed in the semiconductor portion 154 cbetween the third source electrode 173 c and the third drain electrode175 c.

According to an embodiment, a thin film transistor may include a firstthin film transistor and a second thin film transistor each electricallyconnected to the gate line and the data line, and a third filmtransistor electrically connected to the gate line, a terminal of thesecond thin film transistor, and the reference voltage line.

A passivation layer 180 is disposed on the data conductors 171, 173 c,175 a, 175 b, and 175 c, and the exposed semiconductors 154 a, 154 b,and 154 c. The passivation layer 180 may include an organic layer andmay have a flat surface. The organic layer has negative photosensitivityand a dielectric constant thereof may be less than about 4.0,specifically about 3.0 or less, more specifically about 2.0 or less. Thepassivation layer 180 can have a dual-layered structure including alower inorganic layer and an upper organic layer disposed on the exposedregion of the semiconductor 154 in order to sustain the inorganiclayer's excellent insulating characteristics, and to avoid damage to theexposed region of the semiconductors 154 a, 154 b, and 154 c.

The passivation layer 180 includes a first contact hole 185 a, a secondcontact hole 185 b, and a third contact hole 185 c respectively exposingthe first drain electrode 175 a, the second drain electrode 175 b, andthe third drain electrode 175 c.

A pixel electrode 191 including a first subpixel electrode 191 a, and asecond subpixel electrode 191 b, and an assistance storage voltage line137, are disposed on the passivation layer 180. The pixel electrode 191and the assistance storage voltage line 137 may each include atransparent conductive material, such as indium tin oxide (“ITO”) orindium zinc oxide (“IZO”), or a reflective metal such as aluminum,silver, chromium, or alloys thereof.

According to an embodiment, the pixel electrode, may include a firstsubpixel electrode, and a second subpixel electrode separated from eachother, wherein the first subpixel electrode may be electricallyconnected to the first thin film transistor, and the second subpixelelectrode may be electrically connected to the second thin filmtransistor. An output terminal of the second thin film transistor may beelectrically connected to the second subpixel electrode and an inputterminal of the third thin film transistor, according to an embodiment.

According to an embodiment, the assistance storage voltage line may beelectrically connected to the reference voltage line through the thirdthin film transistor and disposed on the data line and the organiclayer.

The first subpixel electrode 191 a and the second subpixel electrode 191b neighbor each other in a column direction, and the overall shapethereof is quadrangular. The first subpixel and the second subpixel eachincludes a cross stem including a transverse stem 192 and a longitudinalstem 193 intersecting the transverse stem. The first and second subpixelelectrodes 191 a and 191 b, are divided into four sub-regions by thetransverse stem 192 and the longitudinal stem 193, and each of thesub-regions includes a plurality of minute branches 194. According to anembodiment, a plurality of minute branches may extend from the crossstem.

A first portion of the minute branches 194 of the first subpixelelectrode 191 a and the second subpixel electrode 191 b are obliquelyextended in a left upper direction from the transverse stem 192 or thelongitudinal stem 193, and a second portion of the minute branches 194are obliquely extended in a right upper direction from the transversestem 192 or the longitudinal stem 193. A third portion of the minutebranches 194 are obliquely extended in a left lower direction from thetransverse stem 192 or the longitudinal stem 193, and a forth portion ofthe minute branches 194 are obliquely extended in a right lowerdirection from the transverse stem 192 or the longitudinal stem 193.

Each of the minute branches 194 forms an angle of about 40 degrees toabout 45 degrees with the gate line 121 or the transverse stem 192. Theminute branches 194 included in the first subpixel electrode 191 a mayform an angle of about 40 degrees with the transverse stem 192, and theminute branches 194 included in the second subpixel electrode 191 b mayform an angle of about 45 degrees with the transverse stem 192. Also,the minute branches 194 of two neighboring sub-regions may be crossed.

The width of the minute branches 194 may be about 3 micrometers (μm) toabout 8 μm, specifically about 4 μm to about 7 μm, more specificallyabout 5 μm to 6 μm. Although not shown, the width of the minute branches194 may be gradually widened.

The first subpixel electrode 191 a and the second subpixel electrode 191b are physically and electrically connected to the first drain electrode175 a and the second drain electrode 175 b through the contact holes 185a and 185 b, respectively, and receive the data voltage from the firstdrain electrode 175 a and the second drain electrode 175 b. According toan embodiment, a part of the data voltage applied to the second drainelectrode 175 b is divided through the third source electrode 173 c,such that the magnitude of the voltage applied to the second subpixelelectrode 191 b may be smaller than that of the voltage applied to thefirst subpixel electrode 191 a. Accordingly, the voltage applied to thefirst subpixel electrode 191 a and the second subpixel electrode 191 bis positive, and in contrast, in an embodiment wherein the voltageapplied to the first subpixel electrode 191 a and the second subpixelelectrode 191 b is negative, the voltage applied to the first subpixelelectrode 191 a is smaller than the voltage applied to the secondsubpixel electrode 191 b.

An area of the second subpixel electrode 191 b may be approximately oneto two times less than that of the first subpixel electrode 191 a.

The assistance storage voltage line 137 is positioned at a portioncorresponding to each data line 171, and includes a connecting member138 extending toward the protrusion 134 of the main storage electrodeline 131. The connecting member 138 is connected to the third drainelectrode 175 c through the third contact hole 185 c. The protrusion 134of the reference voltage line 131 is applied with a reference voltage(“Vcst”) such that the reference voltage (“Vcst”) has a constant voltageand is applied to the third thin film transistor through the third drainelectrode 175 c. As a result, the voltage applied to the second subpixelelectrode 191 b is decreased.

According to an embodiment, the reference voltage line may include aprotrusion overlapping one terminal of the third thin film transistor,and the assistance voltage line may include a connecting memberextending toward the protrusion of the reference voltage line.

A lower alignment layer 12 is disposed on the pixel electrode 191.

Next, the upper display panel, e.g. second substrate 200 will bedescribed, referring to FIG. 1 to FIG. 3.

A light blocking member 220 is disposed on an insulation substrate 210,wherein the insulation substrate includes a transparent glass or aplastic. The light blocking member 220, e.g., a black matrix, reduces orprevents light leakage.

A plurality of color filters 230 are disposed on the substrate 210 andthe light blocking member 220. A portion of the color filters 230 aredisposed in a region enclosed by the light blocking member 220, and mayextend in a direction of a column of the pixel electrode 191. Each colorfilter 230 may display one of three primary colors such as red, green,or blue. However, the color filter is not limited to the three primarycolors red, green, and blue, and may display cyan, magenta, yellow, or awhite-based color.

At least one of the light blocking member 220 and the color filter 230may be disposed on the lower substrate 110.

An overcoat 250 is disposed on the color filter 230 and the lightblocking member 220. The overcoat 250 may include an insulatingmaterial, which reduces or prevents the color filter 230 from beingexposed, and may further include a flat surface. The overcoat 250 may beomitted.

A common electrode 270 is disposed on the overcoat 250.

An upper alignment layer 22 is disposed on the common electrode 270.

Two polarizers (not shown) are disposed on the outer surface of thedisplay panels 100 and 200, a polarization axis of the two polarizersare crossed, and a polarization axis thereof may be parallel to the gatelines 121. According to an embodiment, a reflective liquid crystaldisplay includes a configuration wherein one of the two polarizers maybe omitted.

According to an embodiment, when a data voltage is applied to the firstsubpixel electrode 191 a and the second subpixel electrode 191 b, thefirst subpixel electrode 191 a and the second subpixel electrode 191 bgenerate an electric field, together with the common electrode 270 ofthe upper display panel 200, which receives a common voltage. Theelectric field determines a direction of the liquid crystal molecules ofthe liquid crystal layer 3 between the two electrodes 191 a and 191 b,and the common electrode 270. Polarization of light which transmitsthrough the liquid crystal layer 3 differs depending on the direction ofthe liquid crystal molecules.

According to an embodiment, the first and second subpixel electrodes 191a and 191 b respectively, and the common electrode 270, form liquidcrystal capacitors, to maintain the applied voltage after the thin filmtransistor is turned off. An edge of a minute branch 194 forms ahorizontal component perpendicular to an edge of a minute branch 194,and an inclination direction of liquid crystal molecules is determinedin a direction determined by the horizontal component. According to anembodiment, the liquid crystal molecules initially tend to incline in adirection perpendicular to an edge of a minute branch 194. However, adirection, of the horizontal components of the electric field by an edgeof the neighboring minute branch 194 are opposite, and an intervalbetween the minute branch 194 is narrow such that the liquid crystalmolecules that tend to incline in an opposite direction to each otherare tilted in a direction parallel to a length direction of a minutebranch 194.

According to an embodiment, the length directions in which the minutebranches 194 of one pixel extend are four directions, such that theinclined directions of the liquid crystal molecules are four directions.Therefore, a viewing angle of the liquid crystal display is widened byvarying the inclined directions of the liquid crystal molecules.

The lower and upper alignment layers 12 and 22 according to an exemplaryembodiment include a compound represented by Chemical Formula A below.

In Chemical Formula A, Y1 is a functional group which may facilitate areaction of a photoinitiator and a free radical and may be a thiol grouprepresented by Chemical Formula 1 below.

In Chemical Formula 1, m is 1-5.

Y2 is a functional group which may have a bridge function in a radicalreaction, and may be a vinyl group represented by Chemical Formula 2below.

Y3 is a functional group which may have a monomer which functions toform a pre-tilt of liquid crystal molecules of the liquid crystal layerand a radical reaction, and may be a methacrylate group represented byChemical Formula 3 below.

X is a functional group, which may facilitate aligning liquid crystalmolecules of the liquid crystal layer 3, and may be an alkoxide grouprepresented by Chemical Formula 4 below.

In Chemical Formula 4, n is 1 to 5.

M is a functional group which may improve phase separation and may be amethyl group.

R is a functional group which may enhance reliability and/or a physicalproperty of an upper and/or lower alignment layer, and may be a hydroxylgroup.

According to an embodiment, the lower and upper alignment layers eachinclude a compound represented by Chemical Formula A, wherein Y1 is afunctional group represented by Chemical Formula 1, Y2 is a functionalgroup represented by Chemical Formula 2, Y3 is a functional grouprepresented by Chemical Formula 3, X is a functional group representedby Chemical Formula 4, M is a methyl group, and R is a hydroxyl group.

According to an embodiment, the lower alignment layer and upperalignment layer may each further comprise a functional group representedby Chemical Formula 1. According to an embodiment, the lower alignmentlayer and upper alignment layer may each further comprise a vinylfunctional group. The vinyl functional group may be a vinyl grouprepresented by Chemical Formula 2. According to an embodiment, the loweralignment layer and upper alignment layer may each further comprise amethacrylate functional group. The methacrylate functional group may bea methacrylate group represented by Chemical Formula 3.

According to an embodiment, the functional group Y1, represented byChemical Formula 1, may accelerate a radical reaction of themethacrylate group and the vinyl group. This radical reaction increasesthe reaction along with a radical residue, wherein the passivation layer180 includes the organic layer having negative photosensitivity, whereinthe passivation layer includes the radical residue. While not wishing tobe bound by theory, it is believed a greenish defect of the organiclayer, emitting light of a visible light region, may thus be improved.

Next, the greenish defect will be further described.

According to an embodiment, to increase sensitivity, the organic layerhaving the negative photosensitivity may include a photoinitiatorrepresented by Chemical Formula 5 below.

The photoinitiator represented by Chemical Formula 5 is dissolved in aphotolithography process to form a residue represented by ChemicalFormula 6 below.

According to an embodiment, if ultraviolet rays are irradiated to theresidue represented by Chemical Formula 6 in the following process,first free radicals represented by Chemical Formula 7 and ChemicalFormula 8 are formed.

If the first free radicals represented by Chemical Formula 7 andChemical Formula 8 are combined with each other, a compound including ahighly conjugated double bond is formed such that visible light of thevisible light region is emitted, thereby generating a greenish defect.

According to an embodiment, a method of improving the greenish defect ofthe alignment layer of the present exemplary embodiment is improved asfollows.

Firstly, when ultraviolet rays are irradiated on to the alignment layerrepresented by Chemical Formula B, a radical represented by ChemicalFormula 9 below is formed.

In Chemical Formula B, Y is —S—H, Z is [—O—]_(n), wherein n is 0 or 1.

In Chemical Formula 9, Y is —S., e.g. a thiyl free radical, and Z is[—O—]_(n) wherein n is 0 or 1.

The second free radical represented by Chemical Formula 9 included in atleast one of the lower alignment layer and the upper alignment layereffectively or substantially removes the first free radical representedby Chemical Formula 7 and the first free radical represented by ChemicalFormula 8, thereby reducing or preventing the formation of a compoundincluding a double bond formed from a reaction of the first freeradicals represented by Chemical Formula 7 and Chemical Formula 8.Accordingly, the greenish defect, due to the conjugated double bond ofthe compound formed from a reaction of the first free radicalsrepresented by Chemical Formula 7 and Chemical Formula 8, may be reducedor prevented.

According to an embodiment, at least one of the lower alignment layerand the upper alignment layer may include a second free radical. Thesecond free radical may be represented by Chemical Formula 9. At leastone of the lower alignment layer and the upper alignment layer mayfurther include a compound represented by Chemical Formula B, whereinthe compound may include the second free radical.

As described above, according to an embodiment, the second free radicalincluded in at least one of the lower alignment layer and upperalignment layer may react with at least one of the first free radicalincluded in the organic layer having negative photosensitivity.Accordingly, a greenish defect emitting light of the visible lightregion may be improved.

Next, a liquid crystal display according to another exemplary embodimentwill be described with reference to FIG. 4 and FIG. 5.

FIG. 4 is a plan view of a liquid crystal display according to anotherexemplary embodiment, and FIG. 5 is a cross-sectional view taken alongline V-V of FIG. 4.

Referring to FIG. 4 and FIG. 5, a liquid crystal display according tothe present exemplary embodiment includes a lower display panel 100,e.g. first substrate and an upper display panel 200, e.g. secondsubstrate facing each other, and a liquid crystal layer 3 interposedbetween the two display panels 100 and 200.

First, the lower display panel 100 will be described.

A plurality of gate lines 121, a plurality of step-down gate lines 123,and a plurality of storage electrode lines 125 are disposed on aninsulation substrate 110.

According to an embodiment, a gate line and a step-down gate line may bedisposed on the lower display panel, e.g. first substrate, and a dataline may intersect the gate line.

The gate lines 121 and the step-down gate lines 123 extend in a mainlytransverse direction and transmit a gate signal. The gate line 121includes a first gate electrode 124 a, and a second gate electrode 124 bextending in an upward and a downward direction, and the step-down gateline 123 includes a third gate electrode 124 c protruding in an upwarddirection. The first gate electrode 124 a and the second gate electrode124 b are connected to each other to form one protrusion.

The storage electrode lines 125 extend in a mainly transverse direction,and transmit a predetermined voltage, such as a common voltage. Thestorage electrode line 125 includes a storage electrode 129 protrudingin an upward and a downward direction, a pair of longitudinal portions128 extending almost perpendicular to the gate line 121 and in adownward direction, and a transverse portion 127 connecting the ends ofa pair of longitudinal portions 128 to each other. The transverseportion 127 includes a storage expansion 126 extended in a downwarddirection.

A gate insulating layer 140 is disposed on the gate line 121, thestep-down gate line 123, and the storage electrode line 125.

A plurality of semiconductor stripes (not shown), wherein eachsemiconductor stripe includes a hydrogenated amorphous silicon (a-Si), apolysilicon, or the like, are disposed on the gate insulating layer 140.The semiconductor stripes (not shown) extend in a mainly verticaldirection, and each semiconductor stripe (not shown) includes a firstand a second semiconductor 154 a and 154 b respectively, extendingtoward the first and second gate electrodes 124 a and 124 brespectively, and connected to each other, and a third semiconductor 154c connected to the second semiconductor 154 b. The third semiconductor154 c is extended, thereby forming a fourth semiconductor 157.

A plurality of ohmic contact stripes (not shown) are disposed on thesemiconductor stripes (not shown), wherein a first ohmic contact (notshown) is disposed on the first semiconductor 154 a, and a second ohmiccontact 164 b and a third ohmic contact (not shown) are disposed on thesecond semiconductor 154 b and the third semiconductor 154 c,respectively. The ohmic contact stripes include a first protrusion (notshown) forming a pair along with a first ohmic contact island anddisposed on the first protrusion of the semiconductor, a secondprotrusion (not shown) forming a pair along with a second ohmic contactisland and disposed on the second protrusion of the semiconductor, and athird protrusion (not shown) forming a pair along with a third ohmiccontact island and disposed on the third protrusion of thesemiconductor. The third ohmic contact is extended, thereby forming afourth ohmic contact 167.

A data conductor including a plurality of data lines 171, a plurality offirst drain electrodes 175 a, a plurality of second drain electrodes 175b, and a plurality of third drain electrodes 175 c, is disposed on eachof the ohmic contacts 164 b and 167.

The data lines 171 transmit data signals and extend in a longitudinaldirection thereby intersecting the gate lines 121 and the step-down gatelines 123. Each data line 171 includes a first source electrode 173 aand a second source electrode 173 b forming a “W” shape together andextending in a direction towards a first gate electrode 124 a and asecond gate electrode 124 b.

The first drain electrode 175 a, the second drain electrode 175 b, andthe third drain electrode 175 c have one end portion having a wide areaand the other end portion configured in a linear shape. The bar endportions of the first drain electrode 175 a and the second drainelectrode 175 b are partially enclosed by the first source electrode 173a and the second source electrode 173 b. The wide end portion of thesecond drain electrode 175 b is again extended thereby forming a thirdsource electrode 173 c configured in a “U” shape. An expansion 177 c ofthe third drain electrode 175 c overlaps the storage expansion 126thereby forming a step-down capacitor (“Cstd”), and a bar end portion ispartially enclosed by the third source electrode 173 c.

The first, second, and third gate electrodes, 124 a, 124 b, and 124 c,respectively, the first, second, third source electrodes, 173 a, 17313,and 173 c, respectively, and the first, second, and third drainelectrodes, 175 a, 175 b, and 175 c, respectively, form a first, second,and third thin film transistor (“TFT”) Qa, Qb, and Qc, respectively,along with the first, second, and third semiconductors 154 a, 154 b, and154 c. A channel of the first, second, and third thin film transistorsis formed in a portion of the first, second, and third semiconductors,154 a, 154 b, and 154 c, respectively, between the source electrodes 173a, 173 b, and 173 c, respectively, and the drain electrodes 175 a, 175b, and 175 c, respectively.

According to an embodiment, a thin film transistor may include a firstthin film transistor and a second thin film transistor each connected tothe gate line and the data line, and a third thin film transistorconnected to the step-down gate line.

According to an embodiment, the gate line may simultaneously transmit agate signal to at least one control terminal of the first thin filmtransistor, the second thin film transistor, and the third thin filmtransistor.

Also, the semiconductor stripes (not shown) including the semiconductors154 a, 154 b, and 154 c, except for the channel region between thesource electrodes 173 a, 173 b, and 173 c and the drain electrodes 175a, 175 b, and 175 c have substantially the same shape as the dataconductors 171, 175 a, 175 b, and 175 c and the ohmic contacts 164 b and167. That is, the semiconductor stripes (not shown) including thesemiconductors 154 a, 154 b, and 154 c have a portion that is exposedwithout being covered by the data conductors 171, 175 a, 175 b, and 175c, and a portion between the source electrodes 173 a, 173 b, and 173 cand the drain electrodes 175 a, 175 b, and 175 c.

A passivation layer 180 is disposed on the data conductors 171, 175 a,175 b, 175 c, and the exposed semiconductors 154 a, 154 b, and 154 c.

The passivation layer 180 may include an organic layer and may have aflat surface. The organic layer has negative photosensitivity and adielectric constant thereby may be less than about 4.0 or less,specifically about 3.0 or less, more specifically about 2.0 or less. Thepassivation layer 180 may have a dual-layered structure including alower inorganic layer and an upper organic layer disposed on the exposedregion of the semiconductors 154 a, 154 b, and 154 c. While not wishingto be bound by theory, it is believed, the dual-layered structure mayfacilitate sustaining the inorganic layer's excellent insulatingcharacteristic and not damaging the exposed region of the semiconductors154 a, 154 b, and 154 c.

The passivation layer 180 includes a plurality of first contact holes185 a and a plurality of second contact holes 185 b exposing the wideend of the first drain electrode 175 a and the wide end of the seconddrain electrode 175 b.

A plurality of pixel electrodes 191 are disposed on the passivationlayer 180.

According to an embodiment, the pixel electrode may include a firstsubpixel electrode and a second subpixel electrode separated from eachother, wherein the first subpixel electrode may be connected to thefirst thin film transistor, and the second subpixel electrode may beconnected to the second thin film transistor. A storage electrode mayoverlap a terminal of the third thin film transistor, according to anembodiment.

The first subpixel electrode 191 a and the second subpixel electrode 191b neighbor each other in a column direction, and are configured in aquadrangular form. The first subpixel and the second subpixel eachincludes a cross stem, including a transverse stem 192 and alongitudinal stem 193 intersecting the transverse stem. The first andsecond subpixel electrodes 191 a and 191 b, are divided into foursub-regions by the transverse stem 192 and the longitudinal stem 193,and each of the sub-regions includes a plurality of minute branches 194.According to an embodiment, the plurality of minute branches may extendfrom the cross stem.

A first portion of the minute branches 194, of the first subpixelelectrode 191 a, and the second subpixel electrode 191 b, are obliquelyextended in a left upper direction, from the transverse stem 192, or thelongitudinal stem 193, and a second portion of the minute branches 194,are obliquely extended in a right upper direction, from the transversestem 192, or the longitudinal stem 193. A third portion of the minutebranches 194 are obliquely extended in a left lower direction, from thetransverse stem 192, or the longitudinal stem 193, and a forth portionof the minute branches 194, are obliquely extended in a right lowerdirection, from the transverse stem 192, or the longitudinal stem 193.

Each of the minute branches 194, forms an angle of about 40 degrees toabout 45 degrees, with the gate line 121 or the transverse stem 192. Theminute branches 194 included in the first subpixel electrode 191 a mayform an angle of about 40 degrees with the transverse stem 192, and theminute branches 194 included in the second subpixel electrode 191 b mayform an angle of about 45 degrees with the transverse stem 192. Also,the minute branches 194 of two neighboring sub-regions may be crossed.

The width of the minute branches 194, may be about 3 μm to about 8 μm,specifically about 4 μm to about 7 μm, more specifically about 5 μm to 6μm. Also, although not shown, the width of the minute branches 194 maybe gradually widened.

The first subpixel electrode 191 a and the second subpixel electrode 191b include an outer stem enclosing an outer perimeter, and a longitudinalportion of the stem extends in a direction of the data line 171 andprevents capacitive coupling between the data line 171 and the firstsubpixel electrode 191 a and the second subpixel electrode 191 b.

The first subpixel electrode 191 a and the second subpixel electrode 191b receive the data voltage from the first drain electrode 175 a and thesecond drain electrode 175 b through the first contact hole 185 a andthe second contact hole 185 b.

A lower alignment layer 12 is disposed on the pixel electrode 191.

Next, the upper display panel 200 will be described.

A light blocking member 220 is disposed on an insulation substrate 210,wherein the insulation substrate includes a transparent glass or aplastic. The light blocking member 220 reduces or prevents lightleakage.

A plurality of color filters 230 are disposed on the substrate 210 andthe light blocking member 220. A portion of the color filters 230 aredisposed in a region enclosed by the light blocking member 220, and mayextend in a direction of a column of the pixel electrode 191. Each colorfilter 230 may display one of three primary colors such as red, green,and blue. However, it is not limited to the three primary colors red,green, and blue, and may display one of cyan, magenta, yellow, or awhite-based color.

At least one of the light blocking member 220 or the color filter 230may be disposed on the lower substrate 110.

A common electrode 270 is disposed on the color filter 230. An overcoatpreventing the color filter 230 from being exposed and providing a flatsurface may be disposed between the common electrode 270 and the colorfilter 230.

An upper alignment layer 22 is disposed on the common electrode 270.

According to an embodiment, when a data voltage is applied to the firstsubpixel electrode 191 a and the second subpixel electrode 191 b, thefirst subpixel electrode 191 a and the second subpixel electrode 191 bgenerate an electric field, together with the common electrode 270 ofthe upper display panel 200, to thereby determine a direction of theliquid crystal molecules of the liquid crystal layer 3 between the twoelectrodes 191 a and 191 b, and the common electrode 270. The luminanceof light that transmits through the liquid crystal layer 3 differsdepending on the thusly-determined direction of the liquid crystalmolecules.

According to an embodiment, the first and second subpixel electrodes 191a and 191 b respectively, and the common electrode 270, form liquidcrystal capacitors, to maintain the applied voltage after the thin filmtransistor is turned off. An edge of a minute branch 194 forms ahorizontal component perpendicular to an edge of a minute branch 194,and an inclination direction of liquid crystal molecules is determinedin a direction determined by the horizontal component.

According to an embodiment, the liquid crystal molecules incline in adirection parallel to a length direction of a minute branch 194.

According to an embodiment, the length directions in which the minutebranches 194 of one pixel extend are four directions, such that theinclined directions of the liquid crystal molecules are four directions.Therefore, a viewing angle of the liquid crystal display is widened byvarying the inclined directions of the liquid crystal molecules.

The first subpixel electrode 191 a and common electrode 270 form a firstliquid crystal capacitor along with the liquid crystal layer 3interposed between the first subpixel electrode 191 a and the commonelectrode 270, and the second subpixel electrode 191 b and the commonelectrode 270 form a second liquid crystal capacitor along with theliquid crystal layer 3 interposed between the second subpixel electrode191 b and the common electrode 270, to maintain the applied voltageafter the first and second thin film transistors are turned off.

The first and second subpixel electrodes 191 a and 191 b overlap thestorage electrode line 125 as well as the storage electrode 129, therebyforming the first and second storage capacitors, and the first andsecond storage capacitors enhance the voltage maintaining capacity ofthe first and second liquid crystal capacitors.

The storage expansion 126 and the expansion 177 c of the third drainelectrode 175 c overlap each other via the gate insulating layer 140 andthe semiconductor layers 157 and 167 interposed between, to form astep-down capacitor.

Now, a process of an operation of the liquid crystal display accordingto the present exemplary embodiment will be described, referring to FIG.4 and FIG. 5.

The gate line 121 is applied with the first gate signal and thestep-down gate line 123 is applied with the second gate signal. If thefirst gate signal is changed from the gate-off voltage (“Voff”) to thegate-on voltage (“Von”), the first and second thin film transistorsconnected thereto are turned on. Accordingly, the data voltage (“Vd”)applied to the data line 171 is applied to the first and second subpixelelectrodes 191 a and 191 b through the turned on first and second thinfilm transistors. The data voltages (“Vd”) applied to the first andsecond subpixel electrodes 191 a and 191 b are the same. The first andsecond liquid crystal capacitors are equally charged by the differencebetween the common voltage and the data voltage (“Vd”).

Next, if the first gate signal is changed from the gate-on voltage(“Von”) to the gate-off voltage (“Voff”), and simultaneously the secondgate signal is changed from the gate-off voltage (“Voff”) to the gate-onvoltage (“Von”), the first and second thin film transistors are turnedoff and the third thin film transistor is turned on. Thus, the chargesare moved from the second subpixel electrode 191 b to the third drainelectrode 175 c through the third thin film transistor. Accordingly, thecharging voltage of the second liquid crystal capacitor is decreased andthe step-down capacitor is charged. The charging voltage of the secondliquid crystal capacitor is decreased by the capacitance of thestep-down capacitor such that the charging voltage of the second liquidcrystal capacitor is lower than the charging voltage of the first liquidcrystal capacitor.

Charge voltages of two liquid crystal capacitors Clch and Clcl representdifferent gamma curves, and the gamma curve of one pixel voltage is acombination curved line of the different gamma curves. The frontcombination gamma curve coincides with the reference gamma curve at theoptimally-determined front side, and the lateral gamma curveapproximates the front reference gamma curve. Accordingly, the imagedata are converted so that the lateral visibility is improved.

According to an embodiment, referring to FIGS. 1 to 3, the lower andupper alignment layers 12 and 22 each include a compound represented byChemical Formula A.

According to an embodiment, the functional group Y1, represented byChemical Formula 1, may accelerate a radical reaction of themethacrylate group and the vinyl group. The radical reaction increasesthe reaction along with a radical residue, wherein the passivation layer180 includes the organic layer having the negative photosensitivity,wherein the passivation layer includes the radical residue. While notwishing to be bound by theory, it is believed the greenish defect of theorganic layer, emitting light of the visible light region may thus beimproved.

According to an embodiment, a method of manufacturing a liquid crystaldisplay is provided, including disposing a first substrate, a secondsubstrate facing the first substrate, a thin film transistor disposed onthe first substrate, an organic layer disposed on the thin filmtransistor, a pixel electrode disposed on the organic layer, a loweralignment layer disposed on the pixel electrode, a common electrodedisposed on the second substrate, and an upper alignment layer disposedon the common electrode; and contacting at least one of a first freeradical included in the organic layer and a second free radical includedin at least one of the lower alignment layer and the upper alignmentlayer to form a product of the first free radical and the second freeradical disposed on at least one of the lower alignment layer and theupper alignment layer, to manufacture the liquid crystal display.

While this disclosure has been described in connection with what ispresently considered to be practical exemplary embodiments, it is to beunderstood that the invention is not limited to the disclosedembodiments, but, on the contrary, is intended to cover variousmodifications and equivalent arrangements included within the spirit andscope of the appended claims.

What is claimed is:
 1. A liquid crystal display comprising: a firstsubstrate; a second substrate facing the first substrate; a thin filmtransistor disposed on the first substrate; an organic layer disposed onthe thin film transistor; a pixel electrode disposed on the organiclayer; a lower alignment layer disposed on the pixel electrode; a commonelectrode disposed on the second substrate; and an upper alignment layerdisposed on the common electrode, wherein the liquid crystal displaycomprises a product of a first free radical included in the organiclayer and a second free radical included in at least one of the loweralignment layer and the upper alignment layer at the interface betweenthe organic layer and at least one of the lower alignment layer and theupper alignment layer, wherein the lower alignment layer and the upperalignment layer each further comprises a functional group represented byChemical Formula 1:

wherein m is 1-5.
 2. The liquid crystal display of claim 1, wherein thelower alignment layer and the upper alignment layer each furthercomprise a vinyl functional group.
 3. The liquid crystal display ofclaim 2, wherein the lower alignment layer and the upper alignment layereach further comprise a methacrylate functional group.
 4. The liquidcrystal display of claim 3, wherein the organic layer has negativephotosensitivity.
 5. The liquid crystal display of claim 4, wherein thepixel electrode comprises a first subpixel electrode and a secondsubpixel electrode, wherein the first subpixel electrode and the secondsubpixel electrode each comprise a cross stem comprising a transversestem and a longitudinal stem intersecting the transverse stem, and aplurality of branches extending from the cross stem.
 6. The liquidcrystal display of claim 1, further comprising: a gate line and areference voltage line disposed on the first substrate; and a data lineintersecting the gate line.
 7. The liquid crystal display of claim 6,wherein the thin film transistor comprises a first thin film transistorand a second thin film transistor each connected to the gate line andthe data line, and a third thin film transistor connected to the gateline, a terminal of the second thin film transistor, and the referencevoltage line.
 8. The liquid crystal display of claim 7, wherein thepixel electrode comprises a first subpixel electrode and a secondsubpixel electrode separated from each other, wherein the first subpixelelectrode is electrically connected to the first thin film transistor,and the second subpixel electrode is electrically connected to thesecond thin film transistor.
 9. The liquid crystal display of claim 8,further comprising an assistance voltage line electrically connected tothe reference voltage line through the third thin film transistor anddisposed on the data line, wherein the assistance voltage line isdisposed on a same layer as the pixel electrode.
 10. The liquid crystaldisplay of claim 9, wherein the reference voltage line comprises aprotrusion overlapping a terminal of the third thin film transistor, andthe assistance voltage line comprises a connecting member extendingtoward the protrusion of the reference voltage line.
 11. The liquidcrystal display of claim 8, wherein an output terminal of the secondthin film transistor is electrically connected to the second subpixelelectrode and an input terminal of the third thin film transistor. 12.The liquid crystal display of claim 11, wherein the first subpixelelectrode and the second subpixel electrode comprise a cross stemcomprising a transverse stem and a longitudinal stem intersecting thetransverse stem, and a plurality of branches extending from the crossstem.
 13. The liquid crystal display of claim 12, wherein each controlterminal of the first thin film transistor, the second thin filmtransistor, and the third thin film transistor is configured tosimultaneously respond to a gate signal transmitted on the gate line.14. The liquid crystal display of claim 1, further comprising a gateline and a step-down gate line disposed on the first substrate, and adata line intersecting the gate line.
 15. The liquid crystal display ofclaim 14, wherein the thin film transistor comprises a first thin filmtransistor and a second thin film transistor each connected to the gateline and the data line, and a third thin film transistor connected tothe step-down gate line.
 16. The liquid crystal display of claim 15,wherein the pixel electrode comprises a first subpixel electrode and asecond subpixel electrode separated from each other, wherein the firstsubpixel electrode is electrically connected to the first thin filmtransistor, and the second subpixel electrode is electrically connectedto the second thin film transistor.
 17. The liquid crystal display ofclaim 16, further comprising a storage electrode overlapping a terminalof the third thin film transistor.
 18. The liquid crystal display ofclaim 1, wherein the first free radical is represented by ChemicalFormula 7 or Chemical Formula 8:


19. The liquid crystal display of claim 1, wherein the second freeradical is represented by Chemical Formula 9:

wherein Y is —S., Z is (—O—)_(n), and n is 0 or 1.